1. Field of the Invention
This invention relates to piston type and/or diaphragm type hand operated double acting liquid or fuel transfer pumps and the like.
2. Description of the Prior Art
It is well recognized in the industry that in order to remain competitive from a cost basis, it is often necessary to avoid incorporating elaborate or expensive features which, although, might be advantageous from a durability standpoint, the cost thereof can not be justified. For example, it is well known that friction creates wear particularly between two moving parts. Therefore, in order to eliminate or at least minimize friction, bearing assemblies, i.e., roller bearings, ball bearings and sleeve bearings and the like, may be incorporated when it is highly desirable to minimize friction. Of course, the more elaborate or sophisticated a product becomes, the greater is the cost thereof, which in many cases adversely affects the sales volume thereof. Accordingly, the secret of a successful product oftentimes lies in the simplicity in the construction thereof. Of course, the consumer still demands a certain degree of reliability and durability for the product purchased, therein lies the main objective of the present invention.
Heretofore, pumps of the type herein disclosed usually incorporated floated pivot pin structure for coupling the lever like hand operated lever or handle to the reciprocatable rod which actuates the piston in piston type pumps or the diaphragm in diaphragm type pumps, i.e., the floating pin is free to revolve in both the reciprocating rod and the lever. This arrangement has proven to have several disadvantages which invariably lead to premature failure of the pump. More specifically, the prevailing problem involves undue wear of the pivot pin structure or of the handle or lever in the vicinity immediately about the pivot pin structure. Many of the failures resulted from deep grooves being worn in the pivot pin structure until the pin structure broke at the groove or grooves. Of course, the obvious solution to this problem would be to incorporate any of the above mentioned types of friction reducing bearings for receiving the pin structure, however, the cost of such an arrangement can not be fully justified. Therefore, the industry has learned to live with this drawback by simple overhauling or oftentimes replacing these type pumps.
Accordingly, a need exists for an improvement of this coupling arrangement which minimizes wear of the handle or lever. However, the solution must reside in simplicity and ease of construction and assembly, thus minimizing the overall cost in order to remain competitive.